WO2023036366A1

WO2023036366A1 - Drive unit for motor-vehicle applications

Info

Publication number: WO2023036366A1
Application number: PCT/DE2022/100623
Authority: WO
Inventors: Peter Szegeny; Michael Scholz; Holger Schiffer
Original assignee: Kiekert Ag
Priority date: 2021-09-09
Filing date: 2022-08-19
Publication date: 2023-03-16
Also published as: DE102021123331A1

Abstract

The invention relates to a drive unit for motor-vehicle applications, comprising an electromotive drive (7 to 15) and an actuation rod (7) which is mounted, at one end, on the drive (7 to 15) and is acted upon by the drive. The drive (7 to 15) acts eccentrically on the actuation rod (7), wherein for this purpose a drive cam (9) of the drive (7 to 15) engages in a drive cut-out (10) of the actuation rod (7). Moreover, a guide cam (11), which engages in a guide cut-out (12) in the actuation rod (7), is provided. The drive cam (9) and the guide cam (11) are arranged at a drive wheel (15) of the electromotive drive (7 to 15). According to the invention, the electromotive drive (7 to 15) has at least one evoloid gear stage (14a, 15a).

Description

Drive unit for motor vehicle technical applications

The invention relates to a drive unit for motor vehicle applications, with an electric motor drive and with an actuating rod mounted at one end on the drive and acted upon by it, the drive working eccentrically on the actuating rod and for this purpose a drive cam of the drive engaging in a drive recess of the actuating rod , wherein a guide cam engaging in a guide recess in the actuating rod is also provided, and wherein the drive cam and the guide cam are arranged on a drive wheel of the electric motor drive.

Drive units for motor vehicle applications are used in a variety of ways. These include, for example and not restrictively, locking and/or opening devices for motor vehicle doors, as described in detail in WO 2015/024555 A1. With the help of such a closing device, a vehicle flap, a vehicle side door, a bonnet, etc. can be pulled shut, for example, from a pre-closed position to a main closed position against the force of a peripheral rubber door seal. Such a drive unit can also generally be used to implement an opening device for opening such a flap, hood or side door.

Another application for automotive drive units is described in DE 197 37 996 A1. Here, the drive unit ensures that a striker carrier is moved linearly with the help of the local electric motor drive. The striker interacts in a known manner with a motor vehicle door lock, which in turn in or on a Motor vehicle door is attached. In this way, a motorized closing aid can be implemented.

In addition to the described applications of such a drive unit for raft vehicle applications as a kind of opening or closing aid for an associated motor vehicle flap, motor vehicle hood, motor vehicle side door, etc., such drive units can of course also be used for other purposes. For example, such a drive unit can also be used in connection with a window winder, as a mirror adjustment, seat adjustment, etc. In addition, applications inside a motor vehicle lock are conceivable and are expressly included in that a locking mechanism consisting of a rotary latch and a pawl is electrically opened with the aid of the drive unit.

All of the applications described are characterized in that the electric motor drive is typically operated with a low direct current voltage of, for example, 12 V that is available in the motor vehicle and is consequently limited in terms of its power. In practice, this is taken into account by the fact that a downstream gear or a special design of the actuating rod causes an increase in the torque on the output side of the electric motor drive in order to be able to realize and implement the closing and opening processes described, which may require high forces. This sometimes requires considerable design effort.

For this reason, the generic prior art according to DE 10 2019 1 19 876 A1 uses an actuating rod which is acted upon using a double cam arrangement. This is because the actuating rod is acted upon using the drive cam and, in addition, the guide cam. As a result, the overall design effort is reduced. At the same time, if necessary, high torques can be applied to the drive cam using the drive cam Transfer operating rod, because this torque ultimately depends on the point of contact of the drive cam in question in the drive recess and the direction of force defined in this way between the drive cam and the actuating rod. The torque that is realized can consequently also be specified variably overall, depending on the geometric design. The additionally provided guide cam always ensures that the actuating rod is guided and reset correctly at the same time and unchanged.

Neither a spring nor additional guide means or rail guides are required for this. Because the design with the two cams in conjunction with the associated recesses means that the actuating rod is guided with no or almost no play. This has basically worked.

A comparable and also generic prior art is described in EP 2 163 715 A1. In this case, too, a double cam control of an actuating rod is used in order to be able to open the locking mechanism of an associated motor vehicle lock.

The state of the art has proven itself in principle, but still offers room for improvement. The known drive unit thus opens up the possibility of being able to act on an actuating rod with perfect guidance and with variable torque within certain limits. However, there are still requirements in practice that aim to further reduce the design effort and also the number of parts and thus the weight of such a drive unit. In fact, it is usually worked in such a way that the drive wheel, which has the double-cam design, is acted upon by an electric motor via several gear stages. These multiple gear stages ensure that the high-speed rotations of the drive motor are reduced as part of the drive unit and the required torque is available at the drive wheel. This is structurally complex.

The invention is based on the technical problem of further developing such a drive unit in such a way that the design effort is reduced again compared to the prior art.

To solve this technical problem, the invention proposes in a generic drive unit for motor vehicle applications that the electromotive drive has at least one Evoluid gear stage.

As a rule, the procedure is such that only a single evoloid gear stage is implemented. This is advantageously found between a worm on an output shaft of an electric motor and the drive wheel. This means that the drive unit for motor vehicle applications is, according to the invention, reduced to just the electric motor with the worm on its output shaft and the drive wheel, which has the two cams. As a result, a particularly compact design is made available, which is at the same time capable of making enormous torques available to the actuating rod on the output side, which previously had not been thought possible with such a squat structure.

This can essentially be attributed to the fact that at this point the at least one or only Evoloid gear stage is realized between the worm on the output shaft of the electric motor and the drive wheel. Such an evoloid gear stage opens up the possibility of a large ratio spread. In fact, such an evoloid gear stage can be used to provide a reduction in the example that provides values of 10 to 1, 20 to 1, in particular even 30 to 1 and more. That is, in the example case of a reduction of 30 to 1 30 revolutions of the output shaft of the electric motor and consequently of the worm located on the output shaft in just 1 revolution of the drive wheel. In principle, even higher reduction values of up to 50 to 1 or even more are possible and are encompassed by the invention. All this is achieved with the help of the single Evoloid gear stage, i.e. through the engagement of the worm on the output shaft of the electric motor with the drive wheel. Consequently, a high torque is available at the drive wheel, which is transmitted to the actuating rod with the aid of the two cams with no play or almost no play, and without the need for additional springs for resetting, further guides, etc. This is where the main advantages can be seen.

In detail, the design is such that the drive wheel has evoloid teeth on its outer circumference that are inclined relative to its axis of rotation. Consequently, these inclined evoloid teeth define a peripheral evoloid toothing of the drive wheel. The worm also has several evoloid teeth, which are beveled in such a way that at least one evoloid tooth can always engage in the outer peripheral evoloid toothing of the drive wheel.

An embodiment has proven to be particularly favorable in which the worm is equipped with a maximum of three evoloid teeth on the circumference and in its longitudinal extension. These max. three evoloid teeth are again beveled in such a way that at least one of these three evoloid teeth always engages in the outer peripheral evoloid toothing of the drive wheel.

The design of the two cams on the drive wheel is generally such that the guide cam and the drive cam are formed at an acute angle to one another and on the same axis. In addition, it has proven itself in this context if the guide cam, the drive cam and the drive wheel is designed as a one-piece plastic component and in particular a plastic injection molded part. As a result, not only is a particularly weight-optimized and corrosion-free embodiment made available, but the torque transmitted from the drive cam to the actuating rod can also be varied, if necessary, depending on the acute angle between the guide cam and the drive cam. For the reasons already described in the introduction, this ultimately depends on how the direction of force formed by the drive cam at the point of contact in the associated drive recess is oriented towards the actuating rod.

Furthermore, it has proven to be advantageous if the worm and the actuating rod are also each designed as a plastic component and in particular a plastic injection-molded part. As a result, a corrosion-free and weight-optimized embodiment is once again made available, which can also be manufactured in a particularly cost-effective and targeted manner.

It has proven to be particularly favorable if the electromotive drive unit is arranged in a dry room housing part of a drive housing. Such an embodiment is particularly recommended in the event that the electromotive drive unit is part of a motor vehicle lock and in particular a motor vehicle door lock. In this case, the drive housing is designed as a lock housing.

Typically, such a lock housing is designed in two parts with the already mentioned dry room housing part and a wet room housing part. In the wet room housing part there is usually a locking mechanism consisting essentially of a rotary latch and a pawl as further components of the motor vehicle lock. The arrangement of the electromotive drive unit in the dry room housing part ensures that the individual components of the electromotive drive, which are advantageously predominantly made of plastic, are protected against both moisture and moisture penetrating dirt, dust etc. are protected. Because the dry room housing part of the drive housing or lock housing is regularly hermetically sealed against the environment and thus against moisture, dirt and dust. At the same time, this ensures that the electric motor drive functions perfectly, even over long periods of time, as well as low-friction operation.

The invention also relates to a motor vehicle lock and in particular a motor vehicle door lock, which is not only equipped with the above-mentioned locking mechanism consisting essentially of a rotary latch and pawl, but also with the drive unit mentioned and described in detail. In this case, the drive unit or the electric motor drive may ensure what is known as an electrical opening of the locking mechanism. That is, the actuating rod works directly or indirectly on the pawl in the closed state of the locking mechanism and ensures that the pawl is lifted from its latching engagement with the catch. As a result, the rotary latch can open with the help of a spring and release a previously caught locking bolt. The associated motor vehicle door can be opened.

In principle, the electric motor drive inside the motor vehicle lock and in particular the motor vehicle door lock can also be used for other motor actuations, for example to act on an actuating lever system, to the effect that the actuating lever system can, for example, be moved from a "locked" functional position to an "unlocked" functional position “ is transferred. Other functional positions such as "anti-theft/anti-theft" and "child-proof/child-unlocked" can also be realized and implemented with the help of the electromotive drive and the appropriately designed actuating lever chain inside the motor vehicle lock. This is where the main advantages can be seen. The invention is explained in more detail below with reference to a drawing that merely represents an exemplary embodiment; show it:

Fig. 1 the drive unit according to the invention in a

perspective and

Figures 2A and 2B show the dual cam arrangement in detail.

A drive unit for motor vehicle applications is shown in the figures. According to the exemplary embodiment, the drive unit is not limited to a component of a motor vehicle lock and in particular a motor vehicle door lock, of which a lock housing 1, 2 can be seen in FIG. 1 and very schematically. According to the exemplary embodiment, the lock housing 1 , 2 is composed of a dry room housing part 1 and a wet room housing part 2 . In the wet room housing part 2 there is a locking mechanism 3, 4 consisting essentially of a rotary latch 4 and a pawl 3, which are shown in their closed state according to the exemplary embodiment in FIG. It can also be seen that the dry room housing part 1 is separated from the wet room housing part 2 by a partition wall 5 which has only one passage opening 6 for an actuating rod 7 to be described in more detail below. The actuating rod 7 can perform the longitudinal movements indicated in FIG prevent dirt.

In fact, the actuating rod 7 belongs to an electric motor drive 7, 8, 9, 10, 11, 12, 13, 14, 15. It can be seen that the electric motor drive 7 to 15 is equipped with an electric motor 13 which has a worm 14 on its output shaft. The worm 14 meshes with teeth of a drive wheel 15 on the outer circumference. The drive wheel 15 is in turn equipped with a drive cam 9 which engages in a drive recess 10 of the actuating rod 7 . In addition, the drive wheel 15 also has a guide cam 11 which engages in a guide recess 12 in the actuating rod 7 . Finally, the electromotive drive 7 to 15 also includes a bracket 8 connected to the actuating rod 7 with an associated recess into which a pin 3a of the pawl 3 engages.

The drive 7 to 15 works eccentrically on the actuating rod 7. As a result, the actuating rod 7 can perform the linear movements shown in FIG. 1 in its longitudinal direction. As a result, the pawl 3 can be rotated about its axis and thus lifted from its latching engagement with the rotary latch 4 shown in FIG. 1, so that the locking mechanism 3, 4 is opened electrically or by an electric motor.

According to the invention, the illustrated electric motor drive 7 to 15 is equipped with at least one evoloid gear stage 14a, 15a. According to the exemplary embodiment, a single evoloid gear stage 14a, 15a is implemented in the electric motor drive 7 to 15, namely between the worm 14 on the output shaft of the electric motor 13 and the drive wheel 15. For this purpose, the drive wheel 15 has evoloid gears on its outer circumference. teeth 15a. The evoloid teeth 15a are inclined relative to an axis of rotation 16 of the drive wheel 15 .

The worm 14 is also equipped with several evoloid teeth 14a. The evoloid teeth 14a are beveled in such a way that at least one of these evoloid teeth 14a always engages in the evoloid toothing of the drive wheel 15 on the outer circumference. The exemplary embodiment shows that that the worm 14 is equipped with a maximum of three evoloid teeth 14a on the circumference and in its longitudinal extension.

The guide cam 1 1 and the drive cam 9 are arranged at an acute angle to each other according to the embodiment, as can be understood from FIGS. 2A and 2B. In fact, at this point between the two cams 9, 11, the acute angle a drawn there in FIG. 2A is realized. In addition, the two cams 9, 11 are formed with the same axis as each other, namely the axis of rotation 16 of the drive wheel 15 is used as the common axis.

According to the exemplary embodiment, the guide cam 11, the drive cam 9 and the drive wheel 15 define a one-piece or one-piece plastic component 9, 11, 15. The plastic component 9, 11, 15 in question is designed as a plastic injection molded part according to the exemplary embodiment. The worm 4 and the actuating rod 7 including the extension arm 8 are each designed as plastic components and in particular plastic injection molded parts. This enables a particularly cost-effective production and ensures that the evoloid teeth 14a, 15a, which are consequently also made of plastic, and the evoloid gear stage 14a, 15a realized as a result, work with particularly low friction. A largely wear-free operation is also ensured by the fact that the electromotive drive 7 to 15 is predominantly arranged in the drying room housing part 1 and the actuating rod 7 only has the passage opening 6 as the only opening in the drying room housing part 1 as shown in Fig. 1 passes through in order to be able to interact with the locking mechanism 3, 4 in the wet room housing part 2 as described.

2A shows that the two cams 9, 11 are arranged at an acute angle to one another and enclose the angle a between them, which can advantageously assume values between 20° and 60°. Besides is the drive cam 9 according to the embodiment is elliptical, while the guide cam 11 is designed in contrast truncated elliptical. The drive cam 9 and the guide cam 1 1 each have an almost identical shape and approximately congruent size except for the difference that the guide cam 1 1 at its the common axis 16 bzw. Axis of rotation opposite end is blunted. The drive recess 10 on the actuating rod 7 is in turn designed in the manner of a segment of a circle, specifically in relation to the axis or axis of rotation 16. The guide recess 12, on the other hand, has a lenticular shape.

Based on the two different views in FIGS. 2A and 2B and a comparative view, it can be seen that the two recesses 10, 12 on the actuating rod 7 are also arranged and oriented at an acute angle to one another. This becomes clear if one considers the respective axes of symmetry drawn here in accordance with the illustration in FIG. 2B and the associated acute angle β enclosed by the axes of symmetry. In fact, an acute angle ß of about 20° to 60° is observed at this point.

A comparison of FIGS. 1 and 2A, 2B makes it clear that the two recesses 10, 12 are arranged in different planes, namely on the one hand a guide plane and on the other hand a drive plane with overlap. The two cams 9, 11, on the other hand, have the same axis and are firmly connected to one another and, according to the exemplary embodiment, together with the associated drive wheel 15, define the one-piece or one-piece plastic component 9, 11, 15. FIG. 2A shows a rear view of the drive wheel 15 after the FIG. 1, while FIG. 2B shows the associated front view.

With the help of the electric motor drive 1 to 15, depending on a rotary movement of the drive wheel 15, the actuating rod 7 can be moved to that effect be applied that with their help the pawl 3 is lifted from its latching engagement with the rotary latch 4. As a result, the locking bolt caught by the rotary latch 4 is released and the associated motor vehicle door can be opened. The motor vehicle lock in question has been opened electrically in this way.

Reference List

Lock housing 1 , 2

Dry room housing part 1

Wet room housing part 2

Lock 3, 4

pawl 3

spigot 3a

rotary latch 4

partition wall 5

Passage opening 6 electric motor drive 7, 8, 9, 10, 1 1, 12, 13, 14, 15

operating rod 7

outrigger 8

Plastic component 9, 1 1, 15

Drive cam 9

Drive recess 10

Guide cam 1 1

guide recess 12

electric motor 13

Output shaft/worm 14 Evoloid gear stage 14a, 15a

Evoloid teeth 15a, 14a

Drive wheel 15

Axis of rotation 16 Angle a

angle ß

Claims

patent claims

1. Drive unit for motor vehicle applications, with an electric motor drive (7 to 15) and with an actuating rod (7) mounted at one end on the drive (7 to 15) and acted upon by it, the drive (7 to 15) being eccentric works on the actuating rod (7) and for this purpose a drive cam (9) of the drive (7 to 15) engages in a drive recess (10) of the actuating rod (7), with a further engaging in a guide recess (12) in the actuating rod (7). Guide cam (1 1) is provided, and wherein the drive cam (9) and the guide cam (1 1) are arranged on a drive wheel (15) of the electric motor drive (7 to 15), d a through c h g e n n n z e i c h n e t that the electric motor drive (7 to 15) has at least one evoloid gear stage (14a, 15a).

2. Drive unit according to claim 1, characterized in that the single Evoloid gear stage (14a, 15a) is realized between a worm (14) on an output shaft of an electric motor (13) and the drive wheel (15).

3. Drive unit according to claim 1 or 2, characterized in that the drive wheel (15) has on its outer circumference relative to its axis of rotation (16) inclined evoloid teeth (15a).

4. Drive unit according to claim 2 or 3, characterized in that the worm (14) has a plurality of evoloid teeth (14a) which are beveled such that in each case at least one evoloid tooth (14a) fits into the outer peripheral evoloid toothing of the drive wheel ( 15) intervenes.

5. Drive unit according to one of Claims 2 to 4, characterized in that the worm (14) is equipped with a maximum of three evoloid teeth (14a) on the circumference and in its longitudinal extension.

6. Drive unit according to one of claims 1 to 5, characterized in that the guide cam (1 1) and the drive cam (9) at an acute angle (angle a) to each other and coaxial (rotational axis 16) are formed.

7. Drive unit according to one of claims 1 to 6, characterized in that the guide cam (11), the drive cam (9) and the drive wheel (15) are designed as a one-piece plastic component (9, 11, 15), in particular a plastic injection molded part .

8. Drive unit according to one of claims 1 to 7, characterized in that the worm (4) and the actuating rod (7) are each designed as a plastic component, in particular a plastic injection molded part.

9. Drive unit according to one of claims 1 to 8, characterized in that the electromotive drive unit (7 to 15) is arranged for the most part in a dry room housing part (1) of a drive housing (1, 2).

10. Motor vehicle lock, in particular motor vehicle door lock, with a locking mechanism (3, 4) consisting essentially of a rotary latch (4) and pawl (3), characterized by a drive unit according to one of claims 1 to 9.